Regarding to picosecond pulse laser as the laser source used in long-distance ranging, a detail discussion is addressed. With the review of laser pulse ranging and the development of remote laser ranging, we present an idea that picosecond laser pulse is used in long-distance ranging. We briefly introduce the application of picosecond pulse laser in satellite laser ranging, and then analysis the possibility of picosecond laser pulse to be used in long-distance range finder. We design a simple picosecond laser pulses remote laser rangefinder system.